Shirin Ebadi is an Iranian human rights lawyer and recipient of the 2003 Nobel Peace Prize for work as an advocate for the rights of women and children.

A prison guard in Tehran’s infamous Evin prison. (Morteza Nikoubazl/Reuters)

Last week, the Iranian government released Washington Post reporter Jason Rezaian and four other international prisoners. This is, of course, wonderful news. But more than 800 Iranians remain behind bars, imprisoned for their political beliefs, their journalism or their human rights work.

The current Iranian regime has “brutally repressed” its civil society. According to the U.N. secretary general, Iran maintains an ongoing “crackdown” on free expression, with scores of reporters, human rights defenders and activists in jail. Labor leaders, women’s rights supporters and representatives of Iran’s minority communities are all languishing behind bars.

As a human rights lawyer, I have defended many of these men and women in court. I have seen the sham trials that the state runs. Security forces from the Intelligence Ministry and Revolutionary Guard have long been able to arrest who they want, when they want, for whatever reason. These agencies essentially dictate verdicts to Revolutionary Court judges, who see themselves as a extension of the “security” system, not independent arbiters of justice and law.

As a result, political prisoners and prisoners of conscience are deprived a fair trial. Routinely, I see people convicted on vague charges like “propaganda against the state” or “endangering the security of the state.” Almost all are put behind bars for the peaceful expression of their political views, religious beliefs, artistic vision or human rights advocacy. They are being held hostage by security forces against Iranian law and international law.

If Iran’s rulers can release a handful of Iranian American dual nationals, why can’t authorities free the young physicist Omid Kokabee, jailed for refusing to work for Iran’s military? What about human rights lawyer Abdolfattah Soltani, student leader and women’s rights worker Bahareh Hedayat, journalist Issa Saharkhiz, political activist Saeed Madani or hundreds of others?

Why can’t authorities free human rights defender Narges Mohammadi? Mohammadi is vice president of the Defenders of Human Rights Center, an organization I helped establish. She co-founded the coalition Step by Step to Stop the Death Penalty, and has also worked as an investigative journalist. Mohammadi spoke out for victims of torture such as Sattar Beheshti, and briefed foreign dignitaries such as Catherine Ashton. Are these acts grounds for imprisonment?

Apparently so. Six years ago, Mohammadi was sentenced to 11 years in prison. She is currently serving a prison sentence and facing new charges.

 Upon arrest, political detainees are held in solitary confinement, denied access to their lawyers and family and subjected to physical and psychological torture. All this to produce a confession to “crimes” that no true judicial system would ever consider crimes. If they fall ill, political prisoners are regularly denied medical treatment. In Mohammadi’s case, a medical examiner determined in 2012 that she was unable to serve her sentence as a result of poor health. She was granted furlough only to be returned to prison last year. Now she is suffering from paralysis caused by a neurological disorder and only receiving minimal care.

I am overjoyed that Rezaian and three other Iranian American prisoners are now free. But I am incredibly sorry that other prisoners, who possess only Iranian citizenship, remain behind bars.  I hope that some day soon, we witness the release of all political prisoners and prisoners of conscience in Iran.